Active collision avoidance system has received more and more attraction, which has the capability to avoid potential accidents and reduce driver burden. This paper proposes an active collision avoidance system which consists of a path planner and a coordinated lateral controller. In the path planner, cubic B-spline is developed to obtain collision-free trajectories to bypass the obstacle by steering. Based on this, a coordinated lateral dynamic control of autonomous ground vehicles is presented to improve the accuracy and robustness of path following and simultaneously ensure vehicle stability via active front steering and direct yaw moment control. Then, second-order sliding mode control, based on super-twisting algorithm, is applied to reduce lateral offset and heading angle deviation as much as possible and avoid chattering phenomenon of tradition sliding mode control. Meanwhile, a new form of sliding mode control based on improved reaching law is devoted to forcing the vehicle state sideslip angle and yaw rate to stability envelope with less chattering in the case of low road friction coefficient. Eventually, the effectiveness and robustness of active collision avoidance system against external disturbance and parametric uncertainties are confirmed through different test cases in the MATLAB/Simulink simulation platform.
Sliding Mode Control Techniques and Artificial Potential Field for Dynamic Collision Avoidance in Rendezvous Maneuvers
